Reset works, because it is a separate wire that sends that in the A500.

I have a couple of bare ones and J05/06 are not linked in these.

If the caps light stays on, it seems the keyboard can't reset itself properly. I'd probably just swap the 6570 and perhaps the 555 timer, but I've never had that problem myself so I have no prior experience.

Thanks! I'll have an experiment. It looks like the matrix is OK, and that there's no stuck keys, so I guess it must be in the chips.

I've had a quick trace of the circuit and learnt that the reset signal comes from the 74LS27P (U2), as that has a parallel connection to the keyboard matrix. Well, it was interesting to me :D .

Damn and blast: changed the timer chip, and then changed the controller.

Exactly the same: just the caps lock light on permanently.

Time to check every connection again. Damn damn damn damn damn.

Pooballs :(

I had one of those mitsumi pc keyboards back in the day... Unless its hiding in my storage shed but I doubt it :rolleyes

indeed.

Changed the connector. Nothing.
Changed the transistors (3904s) for known good from another keyboard (C458) - that stopped the Amiga from booting... Not surprising, but interesting that different components are used!
Traced every connection on the 6570, and the two gates... All good.
Made a couple of extra wire connections to make sure of connectivity. No change.

I could change the two gates, but I don't suspect 'em given that the reset circuit works.

At a loss to know what to do. I'm starting to trace every connection...

Yeah... thanks for that. (said sarcastically)

I originally called that an "NMB" keyboard, but changed to "NME" when I saw your posts.... because it sounded like you knew what you were talking about. Now, it won't let me edit them back. Not only that, but I went on a keyboard forum (geekhack), calling it an "NME" keyboard - exposing my ignorance for all to see. Yes... thanks. :blased ;)

I've since become a bit of a keyboard fanatic. If I could design my ultimate Amiga keyboard, it would have the layout and size of the A1000, in a metal case, with IBM Model F type buckling spring switches (or orange Alps) and double-shot black keys with white centred text.

(similar to this)
http://geekhack.org/attachment.php?a...3&d=1273100233

Hehe, I've been calling them NMEs for many many years now, so I've embarrassed myself too on many forums. :-)

Anyone happen to know what the A1000 switches are exactly, and where some replacements might be obtained (eg. certain PC keyboards)? I'm not convinced they are Cherry, or at least they must have changed the design at some point.

Looking at that, they certainly don't sport the cherry logo. I think I'll have to dismantle my shoddier A1000 keyboard again and see for myself.

It's a heck of a pain to dismantle, needs desoldering, but if you can be bothered, any help is appreciated :)

In the meanwhile I opened up the switch, and the internal mechanics don't seem similar to Cherry switches either. I don't have a photo of the internals right now but basically there is a spring that bends sideways instead of being compressed.

Here's a photo of the innards too now.

Very Importat Note
 

Hello,
I have a big number of replacement keys available , including key caps for CDTV.

For information:
There are two mitsumi keyboards, one with foil, other with pcb:
http://scacom.bplaced.net/Collection...warttasta1.jpg

VERY IMPORTAT NOTE:
Mitsumi key-foil is SELF DESROYING as discribed on my German homepage. here is a picture
http://scacom.bplaced.net/Collection...warttasta2.jpg
this is inside on nearly every mitsumi keyboard. Dust comes onto the foil, when pressing space etc, space key is destroying the contact foil forcing keyboard to fail. NOTE: Repair nearly is impossible or very heavy work.

Maybe sometimes this part will be translated on exact solution, cause and how to clean. DO NOT CLEAN with WET things, as the foil will be destroyed on the broken parts. Just be sure getting the dust away, maybe make sure this part is protected.

Positions: 2x space (lot of traces), caps lock. Maybe others. As well as RUST on the metal is damaging the foil.


ASK for informations, questions via PM or for replacement keys or parts you need.


There is another keyboard used in Amiga 500. It uses 2 foils to the pcb and is better as mitsumi ones.
gehtjanx

@gehtjanx

Maybe not the right thread for advertising, but ok, do you have any A1000 keyboard related spare parts? All others are common as mud in comparison, it seems :)

sry, no 1000 keyboard parts except cable. CDTV is too very unlikly to find separete keys if they are missing.

Now back to topic, please PM if there are any spare parts questions. If there are questions about the keyboard problems t's in public interest and can be posted here.

thanks,
gehtjanx
(just wrote it here as some are searching parts on page 1)


EDIT:
@ mister_a500:
I saw an Ti 99/4 instead 99/4A, this is a very rare machine, but not mine ;) I do not even have a 99/4A.

FINALLY! I now have a working NMB 500 keyboard :D

Cleaning it up now, as it looks like it's been at the bottom of a cow shed for the last 24 years or so... Sheesh, 24 years.

Seeing as keyboards are an interesting topic, here's one of my hacks..
This is the interface pcb of a Micronik Infinitiv keyboard

http://i298.photobucket.com/albums/m...4/WALKER97.jpg

This is the rear of a CDTV keyboard (Mitsumi build)
http://i298.photobucket.com/albums/m...4/WALKER90.jpg

And some closeups
http://i298.photobucket.com/albums/m...4/WALKER91.jpg

http://i298.photobucket.com/albums/m...4/WALKER92.jpg

This is the rear of an A1200 keyboard
http://i298.photobucket.com/albums/m...4/WALKER94.jpg

I always wanted to make the CDTV keyboard usable as a PS/2 unit. So i thought of combining the A1200 keyboard, CDTV casing, and Micronik pcb.
The A1200 keyboard fits in the casing, meaning that the keys actually fall into place nicely. However, there's a few plastic tabs that prevent the keyboard from "sitting in" properly.

This is where the obstacles are
http://i298.photobucket.com/albums/m...4/WALKER96.jpg

So, they need cutting, and presto!
http://i298.photobucket.com/albums/m.../WALKER113.jpg


Now, the interface is another obstacle itself. The pcb has to be put a bit remote from the ribbon cable, or else the casing's upper and lower halves won't snap. To do this, i decided to unsolder the ribbon socket from the pcb..

http://i298.photobucket.com/albums/m.../WALKER117.jpg

And extend the socket using some cables.
http://i298.photobucket.com/albums/m.../WALKER118.jpg



http://i298.photobucket.com/albums/m.../WALKER121.jpg

This is the whole thing connected
http://i298.photobucket.com/albums/m.../WALKER122.jpg

I can now place it just about any where under the keyboard chassis.
Here's the finished job.
http://i298.photobucket.com/albums/m.../WALKER123.jpg

A1200 in, CDTV out!
http://i298.photobucket.com/albums/m.../WALKER124.jpg

And after testing, it proves working!
http://i298.photobucket.com/albums/m.../WALKER125.jpg

http://i298.photobucket.com/albums/m.../WALKER126.jpg

This is not targeted towards a regular pc usage, but rather to hook up to my Walker replica. I could always use a Keyrah in there and make it USB, but i prefer the PS/2 that pretty much matches the Walker's keyboard socket.

Two words: nice work!

Thanks for those. I've never bothered to take pictures when I've told people before that this can be done..

My CD32 keyboard.

http://i44.tinypic.com/nz3ygi.jpg

Hmmm, that does look very nice. If only they had made more. :-)

Looking for some spare keys for a NMB keyboard if anyone can spare them you can help save a keyboard!

ESC
F5
F10
1
2
Help
Tab
Q
A
Left Shift

Also need one white plastic mount for key.

Thanks!